Simple case of the usual bad owner = bad pet.
As you said Nathan, you talked to the dog, and it was a bigt softy. Brave move tho attacking the owner. If it had been me being attacked with either of my two staffies, you would of been in a hell load of grief. I can't even play fight with the missus without the male attacking me. Any other time he's got upmost respect for me. But, as you said, the dog probably wouldn't of done *BLEEP* to the cat without a little gentle persuasion from the owner.
One thing I hate in life is poeple who bring dogs up to be hard, to fight, to attack people. Because at the end of the day, the only one losing out in the long run is the dog. Be it from losing a fight, or being put down.